// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// $Log:$
//
// DESCRIPTION:
//	The actual span/column drawing functions.
//	Here find the main potential for optimization,
//	 e.g. inline assembly, different algorithms.
//
//-----------------------------------------------------------------------------

static const char rcsid[] = "$Id: r_draw.c,v 1.4 1997/02/03 16:47:55 b1 Exp $";

#include "doomdef.h"

#include "i_system.h"
#include "z_zone.h"
#include "w_wad.h"

#include "r_local.h"

// Needs access to LFB (guess what).
#include "v_video.h"

// State.
#include "doomstat.h"


extern void *n64_memcpy(void *d, const void *s, size_t n);


// ?
#define MAXWIDTH			1120
#define MAXHEIGHT			832

// status bar height at bottom of screen
#define SBARHEIGHT		32

//
// All drawing to the view buffer is accomplished in this file.
// The other refresh files only know about ccordinates,
//  not the architecture of the frame buffer.
// Conveniently, the frame buffer is a linear one,
//  and we need only the base address,
//  and the total size == width*height*depth/8.,
//


byte*		viewimage;
int		viewwidth;
int		scaledviewwidth;
int		viewheight;
int		viewwindowx;
int		viewwindowy;
byte*		ylookup[MAXHEIGHT];
byte*		ylookup2[MAXHEIGHT];

int		columnofs[MAXWIDTH];

// Color tables for different players,
//  translate a limited part to another
//  (color ramps used for  suit colors).
//
byte		translations[3][256];


//
// R_DrawColumn
// Source is the top of the column to scale.
//
lighttable_t*		dc_colormap;
int			dc_x;
int			dc_yl;
int			dc_yh;
fixed_t			dc_iscale;
fixed_t			dc_texturemid;

// first pixel in a column (possibly virtual)
byte*			dc_source;

// just for profiling
int			dccount;

//
// A column is a vertical slice/span from a wall texture that,
//  given the DOOM style restrictions on the view orientation,
//  will always have constant z depth.
// Thus a special case loop for very fast rendering can
//  be used. It has also been used with Wolfenstein 3D.
//
void R_DrawColumn (void)
{
    int			count;
    byte*		dest;
    fixed_t		frac;
    fixed_t		fracstep;

    count = dc_yh - dc_yl;

    // Zero length, column does not exceed a pixel.
    if (count < 0)
    {
	return;
    }

#ifdef RANGECHECK
    if ((unsigned)dc_x >= SCREENWIDTH
	|| dc_yl < 0
	|| dc_yh >= SCREENHEIGHT)
	I_Error ("R_DrawColumn: %i to %i at %i", dc_yl, dc_yh, dc_x);
#endif

    // Framebuffer destination address.
    // Use ylookup LUT to avoid multiply with ScreenWidth.
    // Use columnofs LUT for subwindows?
    dest = ylookup[dc_yl] + columnofs[dc_x];

    // Determine scaling,
    //  which is the only mapping to be done.
    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    // Inner loop that does the actual texture mapping,
    //  e.g. a DDA-lile scaling.
    // This is as fast as it gets.

//    byte fixc = dc_colormap[dc_source[(frac>>FRACBITS)&127]];

    do
    {
	// Re-map color indices from wall texture column
	//  using a lighting/special effects LUT.
	*dest = dc_colormap[dc_source[(frac>>FRACBITS)&127]];

	dest += SCREENWIDTH;
	frac += fracstep;

    }
    while (count--);
}


// UNUSED.
// Loop unrolled.
#if 0
void R_DrawColumn (void) 
{ 
    int			count; 
    byte*		source;
    byte*		dest;
    byte*		colormap;
    
    unsigned		frac;
    unsigned		fracstep;
    unsigned		fracstep2;
    unsigned		fracstep3;
    unsigned		fracstep4;	 
 
    count = dc_yh - dc_yl + 1; 

    source = dc_source;
    colormap = dc_colormap;		 
    dest = ylookup[dc_yl] + columnofs[dc_x];  
	 
    fracstep = dc_iscale<<9; 
    frac = (dc_texturemid + (dc_yl-centery)*dc_iscale)<<9; 
 
    fracstep2 = fracstep+fracstep;
    fracstep3 = fracstep2+fracstep;
    fracstep4 = fracstep3+fracstep;
	
    while (count >= 8) 
    { 
	dest[0] = colormap[source[frac>>25]]; 
	dest[SCREENWIDTH] = colormap[source[(frac+fracstep)>>25]]; 
	dest[SCREENWIDTH*2] = colormap[source[(frac+fracstep2)>>25]]; 
	dest[SCREENWIDTH*3] = colormap[source[(frac+fracstep3)>>25]];
	
	frac += fracstep4; 

	dest[SCREENWIDTH*4] = colormap[source[frac>>25]]; 
	dest[SCREENWIDTH*5] = colormap[source[(frac+fracstep)>>25]]; 
	dest[SCREENWIDTH*6] = colormap[source[(frac+fracstep2)>>25]]; 
	dest[SCREENWIDTH*7] = colormap[source[(frac+fracstep3)>>25]]; 

	frac += fracstep4; 
	dest += SCREENWIDTH*8; 
	count -= 8;
    } 
	
    while (count > 0)
    { 
	*dest = colormap[source[frac>>25]]; 
	dest += SCREENWIDTH; 
	frac += fracstep; 
	count--;
    } 
}
#endif


void R_DrawColumnLow (void)
{
    int			count;
    byte*		dest;
    byte*		dest2;
    fixed_t		frac;
    fixed_t		fracstep;

    count = dc_yh - dc_yl;

    // Zero length.
    if (count < 0)
    {
	return;
    }

#ifdef RANGECHECK
    if ((unsigned)dc_x >= SCREENWIDTH
	|| dc_yl < 0
	|| dc_yh >= SCREENHEIGHT)
    {
	I_Error ("R_DrawColumnLow: %i to %i at %i", dc_yl, dc_yh, dc_x);
    }
    //	dccount++;
#endif

//    dest = ylookup[dc_yl] + columnofs[dc_x<<1];
//    dest2 = ylookup[dc_yl] + columnofs[(dc_x<<1)+1];
    dest = ylookup2[dc_yl] + (dc_x<<1);
    dest2 = ylookup2[dc_yl] + (dc_x<<1)+1;

    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    do
    {
	*dest2 = *dest = dc_colormap[dc_source[(frac>>FRACBITS)&127]];
	dest += SCREENWIDTH;
	dest2 += SCREENWIDTH;
	frac += fracstep;
    }
    while (count--);
}



//
// Spectre/Invisibility.
//
#define FUZZTABLE		50
#define FUZZOFF	(SCREENWIDTH)


int	fuzzoffset[FUZZTABLE] =
{
    FUZZOFF,-FUZZOFF,FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,
    FUZZOFF,FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,
    FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,-FUZZOFF,-FUZZOFF,-FUZZOFF,
    FUZZOFF,-FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,
    FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,-FUZZOFF,FUZZOFF,
    FUZZOFF,-FUZZOFF,-FUZZOFF,-FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,
    FUZZOFF,FUZZOFF,-FUZZOFF,FUZZOFF,FUZZOFF,-FUZZOFF,FUZZOFF 
};

int	fuzzpos = 0;


//
// Framebuffer postprocessing.
// Creates a fuzzy image by copying pixels
//  from adjacent ones to left and right.
// Used with an all black colormap, this
//  could create the SHADOW effect,
//  i.e. spectres and invisible players.
//
void R_DrawFuzzColumn (void)
{
    int			count;
    byte*		dest;
    fixed_t		frac;
    fixed_t		fracstep;

    // Adjust borders. Low...
    if (!dc_yl)
    {
	dc_yl = 1;
    }

    // .. and high.
    if (dc_yh == viewheight-1)
    {
	dc_yh = viewheight - 2;
    }

    count = dc_yh - dc_yl;

    // Zero length.
    if (count < 0)
    {
	return;
    }


#ifdef RANGECHECK
    if ((unsigned)dc_x >= SCREENWIDTH
	|| dc_yl < 0 || dc_yh >= SCREENHEIGHT)
    {
	I_Error ("R_DrawFuzzColumn: %i to %i at %i",
		 dc_yl, dc_yh, dc_x);
    }
#endif


    // Keep till detailshift bug in blocky mode fixed,
    //  or blocky mode removed.
    /* WATCOM code
    if (detailshift)
    {
	if (dc_x & 1)
	{
	    outpw (GC_INDEX,GC_READMAP+(2<<8) );
	    outp (SC_INDEX+1,12);
	}
	else
	{
	    outpw (GC_INDEX,GC_READMAP);
	    outp (SC_INDEX+1,3);
	}
	dest = destview + dc_yl*80 + (dc_x>>1);
    }
    else
    {
	outpw (GC_INDEX,GC_READMAP+((dc_x&3)<<8) );
	outp (SC_INDEX+1,1<<(dc_x&3));
	dest = destview + dc_yl*80 + (dc_x>>2);
    }*/

    // Does not work with blocky mode.
    dest = ylookup[dc_yl] + columnofs[dc_x];

    // Looks familiar.
    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    // Looks like an attempt at dithering,
    //  using the colormap #6 (of 0-31, a bit
    //  brighter than average).
    do
    {
	// Lookup framebuffer, and retrieve
	//  a pixel that is either one column
	//  left or right of the current one.
	// Add index from colormap to index.
	*dest = colormaps[6*256+dest[fuzzoffset[fuzzpos]]];

	// Clamp table lookup index.
	if (++fuzzpos == FUZZTABLE)
	    fuzzpos = 0;

	dest += SCREENWIDTH;

	frac += fracstep;
    }
    while (count--);
}


//
// Framebuffer postprocessing.
// Creates a fuzzy image by copying pixels
//  from adjacent ones to left and right.
// Used with an all black colormap, this
//  could create the SHADOW effect,
//  i.e. spectres and invisible players.
//
void R_DrawFuzzColumnLow (void)
{
    int			count;
    byte*		dest;
    byte*		dest2;
    fixed_t		frac;
    fixed_t		fracstep;

    // Adjust borders. Low...
    if (!dc_yl)
    {
	dc_yl = 1;
    }

    // .. and high.
    if (dc_yh == viewheight-1)
    {
	dc_yh = viewheight - 2;
    }

    count = dc_yh - dc_yl;

    // Zero length.
    if (count < 0)
    {
	return;
    }


#ifdef RANGECHECK
    if (((unsigned)dc_x << 1) >= SCREENWIDTH
	|| dc_yl < 0 || dc_yh >= SCREENHEIGHT)
    {
	I_Error ("R_DrawFuzzColumn: %i to %i at %i",
		 dc_yl, dc_yh, dc_x);
    }
#endif

//    dest = ylookup[dc_yl] + columnofs[dc_x << 1];
//    dest2 = ylookup[dc_yl] + columnofs[(dc_x << 1) + 1];
    dest = ylookup2[dc_yl] + (dc_x<<1);
    dest2 = ylookup2[dc_yl] + (dc_x<<1)+1;

    // Looks familiar.
    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    // Looks like an attempt at dithering,
    //  using the colormap #6 (of 0-31, a bit
    //  brighter than average).
    do
    {
	// Lookup framebuffer, and retrieve
	//  a pixel that is either one column
	//  left or right of the current one.
	// Add index from colormap to index.
	*dest2 = *dest = colormaps[6*256+dest[fuzzoffset[fuzzpos]]];

	// Clamp table lookup index.
	if (++fuzzpos == FUZZTABLE)
        {
	    fuzzpos = 0;
        }

	dest += SCREENWIDTH;
	dest2 += SCREENWIDTH;

	frac += fracstep;
    }
    while (count--);
}


//
// R_DrawTranslatedColumn
// Used to draw player sprites
//  with the green colorramp mapped to others.
// Could be used with different translation
//  tables, e.g. the lighter colored version
//  of the BaronOfHell, the HellKnight, uses
//  identical sprites, kinda brightened up.
//
byte*	dc_translation;
byte*	translationtables;

void R_DrawTranslatedColumn (void)
{
    int			count;
    byte*		dest;
    fixed_t		frac;
    fixed_t		fracstep;

    count = dc_yh - dc_yl;

    if (count < 0)
    {
	return;
    }

#ifdef RANGECHECK
    if ((unsigned)dc_x >= SCREENWIDTH
	|| dc_yl < 0
	|| dc_yh >= SCREENHEIGHT)
    {
	I_Error ( "R_DrawColumn: %i to %i at %i",
		  dc_yl, dc_yh, dc_x);
    }
#endif

    // WATCOM VGA specific.
    /* Keep for fixing.
    if (detailshift)
    {
	if (dc_x & 1)
	    outp (SC_INDEX+1,12);
	else
	    outp (SC_INDEX+1,3);

	dest = destview + dc_yl*80 + (dc_x>>1);
    }
    else
    {
	outp (SC_INDEX+1,1<<(dc_x&3));

	dest = destview + dc_yl*80 + (dc_x>>2);
    }*/

    // FIXME. As above.
    dest = ylookup[dc_yl] + columnofs[dc_x];

    // Looks familiar.
    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    // Here we do an additional index re-mapping.
    do
    {
	// Translation tables are used
	//  to map certain colorramps to other ones,
	//  used with PLAY sprites.
	// Thus the "green" ramp of the player 0 sprite
	//  is mapped to gray, red, black/indigo.
	*dest = dc_colormap[dc_translation[dc_source[frac>>FRACBITS]]];
	dest += SCREENWIDTH;

	frac += fracstep;
    }
    while (count--);
}


//
// R_DrawTranslatedColumnLow
// Used to draw player sprites
//  with the green colorramp mapped to others.
// Could be used with different translation
//  tables, e.g. the lighter colored version
//  of the BaronOfHell, the HellKnight, uses
//  identical sprites, kinda brightened up.
//
//byte*	dc_translation;
//byte*	translationtables;

void R_DrawTranslatedColumnLow (void)
{
    int			count;
    byte*		dest;
    byte*		dest2;
    fixed_t		frac;
    fixed_t		fracstep;

    count = dc_yh - dc_yl;

    if (count < 0)
    {
	return;
    }

#ifdef RANGECHECK
    if (((unsigned)dc_x << 1) >= SCREENWIDTH
	|| dc_yl < 0
	|| dc_yh >= SCREENHEIGHT)
    {
	I_Error ( "R_DrawColumn: %i to %i at %i",
		  dc_yl, dc_yh, dc_x);
    }
#endif

//    dest = ylookup[dc_yl] + columnofs[dc_x << 1];
//    dest2 = ylookup[dc_yl] + columnofs[(dc_x << 1) + 1];
    dest = ylookup2[dc_yl] + (dc_x<<1);
    dest2 = ylookup2[dc_yl] + (dc_x<<1)+1;

    // Looks familiar.
    fracstep = dc_iscale;
    frac = dc_texturemid + (dc_yl-centery)*fracstep;

    // Here we do an additional index re-mapping.
    do
    {
	// Translation tables are used
	//  to map certain colorramps to other ones,
	//  used with PLAY sprites.
	// Thus the "green" ramp of the player 0 sprite
	//  is mapped to gray, red, black/indigo.
	*dest2 = *dest = dc_colormap[dc_translation[dc_source[frac>>FRACBITS]]];
	dest += SCREENWIDTH;
	dest2 += SCREENWIDTH;

	frac += fracstep;
    }
    while (count--);
}


//
// R_InitTranslationTables
// Creates the translation tables to map
//  the green color ramp to gray, brown, red.
// Assumes a given structure of the PLAYPAL.
// Could be read from a lump instead.
//
void R_InitTranslationTables (void)
{
    int		i;

    translationtables = Z_Malloc (256*3+255, PU_STATIC, 0);
    translationtables = (byte *)(( (int)translationtables + 255 )& ~255);

    // translate just the 16 green colors
    for (i=0 ; i<256 ; i++)
    {
	if (i >= 0x70 && i<= 0x7f)
	{
	    // map green ramp to gray, brown, red
	    translationtables[i    ] = 0x60 + (i&0xf);
	    translationtables[i+256] = 0x40 + (i&0xf);
	    translationtables[i+512] = 0x20 + (i&0xf);
	}
	else
	{
	    // Keep all other colors as is.
	    translationtables[i    ] =
            translationtables[i+256] =
            translationtables[i+512] = i;
	}
    }
}


//
// R_DrawSpan
// With DOOM style restrictions on view orientation,
//  the floors and ceilings consist of horizontal slices
//  or spans with constant z depth.
// However, rotation around the world z axis is possible,
//  thus this mapping, while simpler and faster than
//  perspective correct texture mapping, has to traverse
//  the texture at an angle in all but a few cases.
// In consequence, flats are not stored by column (like walls),
//  and the inner loop has to step in texture space u and v.
//
int			ds_y;
int			ds_x1;
int			ds_x2;

lighttable_t*		ds_colormap;

fixed_t			ds_xfrac;
fixed_t			ds_yfrac;
fixed_t			ds_xstep;
fixed_t			ds_ystep;

// start of a 64*64 tile image
byte*			ds_source;

// just for profiling
int			dscount;


//
// Draws the actual span.
void R_DrawSpan (void)
{
    fixed_t		xfrac;
    fixed_t		yfrac;
    byte*		dest;
    int			count;
    int			spot;

#ifdef RANGECHECK
    if (ds_x2 < ds_x1
	|| ds_x1<0
	|| ds_x2>=SCREENWIDTH
	|| (unsigned)ds_y>SCREENHEIGHT)
    {
	I_Error( "R_DrawSpan: %i to %i at %i",
		 ds_x1,ds_x2,ds_y);
    }
//	dscount++;
#endif


    xfrac = ds_xfrac;
    yfrac = ds_yfrac;

    dest = ylookup[ds_y] + columnofs[ds_x1];

    // We do not check for zero spans here?
    count = ds_x2 - ds_x1;

    do
    {
	// Current texture index in u,v.
	spot = ((yfrac>>(16-6))&(63*64)) + ((xfrac>>16)&63);
//	byte spanc = ds_colormap[ds_source[spot]];
	// Lookup pixel from flat texture tile,
	//  re-index using light/colormap.
	*dest++ = ds_colormap[ds_source[spot]];

	// Next step in u,v.
	xfrac += ds_xstep;
	yfrac += ds_ystep;
    }
    while (count--);
}


// UNUSED.
// Loop unrolled by 4.
#if 0
void R_DrawSpan (void) 
{ 
    unsigned	position, step;

    byte*	source;
    byte*	colormap;
    byte*	dest;
    
    unsigned	count;
    usingned	spot; 
    unsigned	value;
    unsigned	temp;
    unsigned	xtemp;
    unsigned	ytemp;
		
    position = ((ds_xfrac<<10)&0xffff0000) | ((ds_yfrac>>6)&0xffff);
    step = ((ds_xstep<<10)&0xffff0000) | ((ds_ystep>>6)&0xffff);
		
    source = ds_source;
    colormap = ds_colormap;
    dest = ylookup[ds_y] + columnofs[ds_x1];	 
    count = ds_x2 - ds_x1 + 1; 
	
    while (count >= 4) 
    { 
	ytemp = position>>4;
	ytemp = ytemp & 4032;
	xtemp = position>>26;
	spot = xtemp | ytemp;
	position += step;
	dest[0] = colormap[source[spot]]; 

	ytemp = position>>4;
	ytemp = ytemp & 4032;
	xtemp = position>>26;
	spot = xtemp | ytemp;
	position += step;
	dest[1] = colormap[source[spot]];
	
	ytemp = position>>4;
	ytemp = ytemp & 4032;
	xtemp = position>>26;
	spot = xtemp | ytemp;
	position += step;
	dest[2] = colormap[source[spot]];
	
	ytemp = position>>4;
	ytemp = ytemp & 4032;
	xtemp = position>>26;
	spot = xtemp | ytemp;
	position += step;
	dest[3] = colormap[source[spot]]; 
		
	count -= 4;
	dest += 4;
    } 
    while (count > 0) 
    { 
	ytemp = position>>4;
	ytemp = ytemp & 4032;
	xtemp = position>>26;
	spot = xtemp | ytemp;
	position += step;
	*dest++ = colormap[source[spot]]; 
	count--;
    } 
} 
#endif


//
// Again..
//
void R_DrawSpanLow (void)
{
    fixed_t		xfrac;
    fixed_t		yfrac;
    byte*		dest;
    int			count;
    int			spot;

#ifdef RANGECHECK
    if (ds_x2 < ds_x1
	|| ds_x1<0
	|| ds_x2>=SCREENWIDTH
	|| (unsigned)ds_y>SCREENHEIGHT)
    {
	I_Error( "R_DrawSpan: %i to %i at %i",
		 ds_x1,ds_x2,ds_y);
    }
//	dscount++;
#endif

    xfrac = ds_xfrac;
    yfrac = ds_yfrac;

//    dest = ylookup[ds_y] + columnofs[ds_x1<<1];
    dest = ylookup2[ds_y] + (ds_x1<<1);

    count = ds_x2 - ds_x1;
    do
    {
	spot = ((yfrac>>(16-6))&(63*64)) + ((xfrac>>16)&63);
	// Lowres/blocky mode does it twice,
	//  while scale is adjusted appropriately.
	*dest++ = ds_colormap[ds_source[spot]];
	*dest++ = ds_colormap[ds_source[spot]];

	xfrac += ds_xstep;
	yfrac += ds_ystep;
    }
    while (count--);
}


//
// R_InitBuffer
// Creats lookup tables that avoid
//  multiplies and other hazzles
//  for getting the framebuffer address
//  of a pixel to draw.
//
void R_InitBuffer ( int width, int height )
{
    int		i;
    int		offset;

    // Handle resize,
    //  e.g. smaller view windows
    //  with border and/or status bar.
    viewwindowx = (SCREENWIDTH-width) >> 1;

    // Column offset. For windows.
    for (i=0 ; i<width ; i++)
    {
	columnofs[i] = viewwindowx + i;
    }

    // Samw with base row offset.
    if (width == SCREENWIDTH)
    {
	viewwindowy = 0;
    }
    else
    {
	viewwindowy = (SCREENHEIGHT-SBARHEIGHT-height) >> 1;
    }

    // Preclaculate all row offsets.
    offset = viewwindowy * SCREENWIDTH;

    for (i=0 ; i<height ; i++)
    {
	ylookup[i] = screens[0] + offset;
        ylookup2[i] = ylookup[i] + viewwindowx;
	offset += SCREENWIDTH;
    }
}


//
// R_FillBackScreen
// Fills the back screen with a pattern
//  for variable screen sizes
// Also draws a beveled edge.
//
void R_FillBackScreen (void)
{
    byte*	src;
    byte*	dest;
    int		x;
    int		y;
    patch_t*	patch;

    // DOOM border patch.
    char	name1[] = "FLOOR7_2";

    // DOOM II border patch.
    char	name2[] = "GRNROCK";

    char*	name;

    if (scaledviewwidth == SCREENWIDTH)
    {
	return;
    }

    if ( gamemode == commercial)
    {
	name = name2;
    }
    else
    {
	name = name1;
    }

    src = W_CacheLumpName (name, PU_CACHE);
    dest = screens[1];

    for (y=0 ; y<SCREENHEIGHT-SBARHEIGHT ; y++)
    {
	for (x=0 ; x<SCREENWIDTH/64 ; x++)
	{
	    n64_memcpy (dest, src+((y&63)<<6), 64);
	    dest += 64;
	}

	if (SCREENWIDTH&63)
	{
	    n64_memcpy (dest, src+((y&63)<<6), SCREENWIDTH&63);
	    dest += (SCREENWIDTH&63);
	}
    }

    patch = W_CacheLumpName ("brdr_t",PU_CACHE);

    for (x=0 ; x<scaledviewwidth ; x+=8)
    {
	V_DrawPatch (viewwindowx+x,viewwindowy-8,1,patch);
    }
    patch = W_CacheLumpName ("brdr_b",PU_CACHE);

    for (x=0 ; x<scaledviewwidth ; x+=8)
    {
	V_DrawPatch (viewwindowx+x,viewwindowy+viewheight,1,patch);
    }
    patch = W_CacheLumpName ("brdr_l",PU_CACHE);

    for (y=0 ; y<viewheight ; y+=8)
    {
	V_DrawPatch (viewwindowx-8,viewwindowy+y,1,patch);
    }
    patch = W_CacheLumpName ("brdr_r",PU_CACHE);

    for (y=0 ; y<viewheight ; y+=8)
    {
	V_DrawPatch (viewwindowx+scaledviewwidth,viewwindowy+y,1,patch);
    }

    // Draw beveled edge.
    V_DrawPatch (viewwindowx-8,
		 viewwindowy-8,
		 1,
		 W_CacheLumpName ("brdr_tl",PU_CACHE));

    V_DrawPatch (viewwindowx+scaledviewwidth,
		 viewwindowy-8,
		 1,
		 W_CacheLumpName ("brdr_tr",PU_CACHE));

    V_DrawPatch (viewwindowx-8,
		 viewwindowy+viewheight,
		 1,
		 W_CacheLumpName ("brdr_bl",PU_CACHE));

    V_DrawPatch (viewwindowx+scaledviewwidth,
		 viewwindowy+viewheight,
		 1,
		 W_CacheLumpName ("brdr_br",PU_CACHE));
}


//
// Copy a screen buffer.
//
void R_VideoErase ( unsigned ofs, int count )
{
    // LFB copy.
    // This might not be a good idea if memcpy
    //  is not optiomal, e.g. byte by byte on
    //  a 32bit CPU, as GNU GCC/Linux libc did
    //  at one point.
    n64_memcpy (screens[0]+ofs, screens[1]+ofs, count);
}


//
// R_DrawViewBorder
// Draws the border around the view
//  for different size windows?
//
void V_MarkRect ( int x, int y, int width, int height );

void R_DrawViewBorder (void)
{
    int		top;
    int		side;
    int		ofs;
    int		i;

    if (scaledviewwidth == SCREENWIDTH)
    {
	return;
    }

    top = ((SCREENHEIGHT-SBARHEIGHT)-viewheight)/2;
    side = (SCREENWIDTH-scaledviewwidth)/2;

    // copy top and one line of left side
    R_VideoErase (0, top*SCREENWIDTH+side);

    // copy one line of right side and bottom
    ofs = (viewheight+top)*SCREENWIDTH-side;
    R_VideoErase (ofs, top*SCREENWIDTH+side);

    // copy sides using wraparound
    ofs = top*SCREENWIDTH + SCREENWIDTH-side;
    side <<= 1;

    for (i=1 ; i<viewheight ; i++)
    {
	R_VideoErase (ofs, side);
	ofs += SCREENWIDTH;
    }

    // ?
    V_MarkRect (0,0,SCREENWIDTH, SCREENHEIGHT-SBARHEIGHT);
}
